I'll echo what Chad said about Hornady brass. I use it exclusively in my Creedmoor, but it does tend to have a short life
if you load near max published data. For some reason my rifle likes a load that is conservative and my brass has lasted 8 cycles with no signs of fatigue so far. As for H4350, some are loading over published max data and are having good results with it. I loaded H4350 for a long time, and then switched to IMR4451 and am a bit more pleased with it. It is a bit cleaner than H4350 and is only a teeny amount slower. Varget is a great powder but it didn't show me anything in the CM. I didn't fool with it for very long as H4350 is obviously the powder of choice.
If you desire you can go to
www.65creedmoor.com and research their site. I have a lot of friends there who eat, sleep, and breath the cartridge. Tons of CM info if you go and read a bit.
EDIT TO ADD: I just went back and re-read your initial post. At 43 grains of H4350 I am assuming you know that you are WAY over any published max load. And I also know that some folks are loading the CM over published data and having satisfactory results. But asking for a 140 grain bullet pushing 3000fps you are dreaming. You can get that with a 120 grain load, but I don't want to be anywhere around if you try to push a 140 to that speed. The creedmoor is very adequate and accurate out to 1000 yards without having to push the speeds up in that area. Just saying ......